1. Field of the Invention
This invention relates to a physical property measuring device, and more particularly to a device for measuring physical properties of a flexible sheet-like test sample made of, for example, a flexible film or the like such as, tensile strength of the test sample or the like.
2. Discussion of the Background
In general, measurement of physical properties of a sheet-like test sample such as tensile strength thereof or the like by means of a physical property measuring device has been conventionally carried out in a manner to clamp the entire upper and lower ends of the test sample through a pair of upper clamp arms and a pair of lower clamps arranged in a measuring zone of the device, respectively, and then apply, to the clamp arms. A tensile force sufficient to cause the test sample to be ruptured, resulting in elongation of the test sample, a rupture point thereof or the like being continuously measured.
Also, measurement of physical properties of the sheet-like test sample such as the thickness thereof, tensile strength thereof or the like requires one to successively feed the test samples to the measuring zone of the physical property measuring device. For the purpose of feeding the test samples to the measuring zone for the measurement, a predetermined number of test samples are kept piled up on a sample stocker. Then, the test samples are laterally successively pushed out one by one from the bottom of the pile by means of an ejector pin. Alternatively, feeding of the test samples is carried out in such a manner that a predetermined number of test samples which are horizontally juxtaposed to one another are extracted one by one by suction through a suction pad in order from one side and then transferred to the measuring zone.
The conventional physical property measuring device exhibits a satisfactory function when the test sample has increased thickness and rigidity. However, when the test sample is made of a flexible sheet-like material such as a flexible film or the like, feeding of the test sample to the measuring zone and suction of the test sample by the suction pad cause the test sample to be deformed and/or wrinkled. Also, a test sample which is curved and/or statically electrified leads to a failure in suspension or hanging of the test sample. Thus, the conventional physical property measuring device fails to constantly carry out stable feeding of the test sample to the measuring zone and satisfactory clamping of the test sample by the clamp arms, leading to a failure in proper measurement of physical properties of the test sample.
Further, in the case that the test sample which is made of a flexible sheet material is clamped at the upper and lower ends thereof through each pair of upper clamp arms and lower clamp arms, fragments of the test sample ruptured in the test are caused to be adhesively held on one of the clamp arms in each pair when the clamp arms in each pair are actuated so as to be open with respect to each other. Thus, the prior art causes automatic removal of the fragments from the clamp arms to be highly difficult or substantially impossible. This is particularly noticeable when the test sample is made of a flexible film material of 1 to 50 .mu.m in thickness, because the test sample is irregularly ruptured to a degree sufficient to fail to permit the fragments of the ruptured test sample to be satisfactorily removed from the clamp arms.